I originally posted this on boardgamegeek, but I thought that it might spark some discussion over here, too. Things have been awfully quiet lately, so I thought that I would throw some fuel on the fire.
Disclaimer: This is pure speculation. I am also playing fast-and-loose with the math. But I trust that FFG will put out a balanced and fun game.
It seems to me that fighters will be an indispensable part of any list. Many of the Rebel Alliance fighters have the bomber trait (X-Wing, Y-Wing, and B-Wing), which allows critical hits to count as hits (they are misses otherwise). Therefore, a single die from a "bomber" fighter will do 0.75 damage on average. For an X-Wing, that is a rate of 5.4 damage per turn per 100 points of investment (a little more than 7 X-Wings). Y-Wings and B-Wings may provide even greater efficiency, since they are dedicated bombers rather than bomber/escorts. Special characters like Luke are also highly efficient cap-ship killers. A Victory II SD can get similar efficiency of attack to an X-Wing (5.3 damage per turn per 100 points of investment for the front arc--when the front arc has a target--plus another 3.5 damage per turn per 100 points from a side arc). However, that only applies when you have targets in your front and side arcs, and it only applies to attacking cap ships. Against fighters, VSD IIs have only 1 blue die (with crits counting as misses; i.e. 0.5 damage per die). This is a miserable 0.59 damage per turn per 100 point investment. Of course, that is not entirely accurate, since a VSD II can do that damage against every single fighter in two arcs. However, smart fighters will swarm their target from every side, so that they cannot be blasted together. So, assuming generously that 3 fighters will be in each arc at a time, that is still a measly 1.8 damage per turn per arc per 100 point investment. Meanwhile, the combined hit-points of all those fighter-bombers exceeds that of the VSD II. Quite simply, an equivalent point value of Rebel fighter-bombers swarming all over a VSD II will easily kill it before it can kill many of them (in a vacuum). At least, that is where my back-of-the-envelope math gets me.
So, the Empire must bring anti-fighter units to the table, or it will collapse under the Rebel bombing runs. The solution is to bring ships with better anti-squadron attacks (per point of investment) or to bring fighters of your own. TIE fighters are the simplest way--even a half-dozen TIEs should be able to keep the Rebel bombers busy long enough to let your Star Destroyers do their thing. An alternate strategy would be to give the Rebels a taste of their own medicine with TIE bombers and their escorts. I would venture to say that it will be impossible to win SW Armada with any consistency without at least 50 points of fighters in your fleet. Many lists will probably take closer to 100 points of fighters.
However, I also do not think that fighters will ever totally dominate the game. First of all, the game is won or lost by destroying capital ships. If you only bring one or two Corvettes and a mess of fighters, then the enemy cap ships should be able to wipe you off the table before the fighters can whittle them down. The victory conditions favor those who bring at least 125 points of capital ships. Secondly, the more fighters that you bring to the table, the more likely it is that enemy anti-squadron attacks will be able to get 3 or more fighters in a single arc. Third, fighters can only take one action (i.e. either move or attack) unless they are supported by a capital ship taking the squadrons action. A fighter-heavy list will not want to have many more squadrons than they have points of squadron rating on their cap ships. So, if you have three cap ships, each with a squadron rating of 2, then you can only effectively command 6 squadrons a turn. Any squadrons in excess of 6 will only be half as effective. In other words, fighters need cap ships in order to unlock their full potential.
I know that this was long and rambly. I could also be wrong about all of it.
TLDR: You will have a hard time if you bring too few or too many fighters. They are an integral but not dominating part of the experience. At least, I hope so...